san francisco police arrested a second suspect. 19-year-old nicholas hudson from daly city. >> this person was seen smashing out the window and vandalizing the muni bus on the 29th. >> reporter: the public helped track hudson down. >> and if it wasn't through the use of social media and the help of the public we wouldn't have been able to capture this person. >> reporter: social media helped police arrest 22-year-old gregory from san francisco. he was caught after this picture went viral. police are hoping the public can help do it again. so they are releasing more pictures from that night. take a look at this man, dressed in dark clothing and a baseball p cay. baseball cap. in addition they are looking for this man, the san francisco chronicle caught a photo of him using a barricade to smash the windshield. she dressed in a red and gray striped long sleeved shirt. and police have not found these arsonists we showed you last week. you can see them setting fire to the bus in this video. >> they are all felony crimes. arson damaging the muni bus. reckless acts on the street.